CHRIS McCALL

Alex Salmond famously said the 2014 independence referendum was a “once in a generation” event. But just how long is such a time frame?

The former First Minister later clarified his remark was a personal opinion. And when the SNP was returned as the largest party at Holyrood in 2016, Nicola Sturgeon made clear she would consider a second referendum on indpendence if there was a “significant and material change” in circumstances – such as Brexit.

Alex Salmond said in 2014 a referendum on Scottish independence was a 'once in a generation' event - but later clarified it as his personal opinion. Picture: Andrew Milligan/PA Wire

Last month the Scottish Parliament backed a second vote, with Sturgeon arguing Scots deserved a choice on whether to remain in the UK post-Brexit or an independent Scotland.

Yet the “once in a generation” line remains a favoured line of attack among Unionist parties opposed to another referendum.

Now a YouGov poll has revealed a majority of Scots consider the term to mean more than 20 years.

A sample of 1,047 adults north of the border found 39% think a generation is 20 or 25 years, 13% say 30 years and 10% say 10 years.

“The Scottish survey did reveal some significant differences between Scots on either side of the independence debate,” said Matthew Smith of YouGov in a blog post.

“While 20 and 25 years were still the most common answers given by both sides, Yes voters were much more likely than No voters to say that a generation lasts fewer than 20 years (28%, compared to 14% of No voters) – although only 2% of Yes voters consider a generation to have passed already.”

“No voters were likewise more likely to say that a generation lasts from 20 to 30 years (59%, compared to 46% of Yes voters).

“Looking at the responses cumulatively, the point at which the majority of Scots say that a generation has passed is 25 years (this is true of both Yes and No voters). If we follow the “once in a generation” logic, these results would dictate that the next Scottish independence referendum be held in 2039.”

When questioned about the “once in a generation” remark, Mr Salmond said last year: “My estimation was that political constitutional referendums are once in a generation and I was making the example of 1979 and 1997 - that is why I always put it in that context every single time I said that.

“Well since the referendum there has been 56 SNP MPs elected out of 59, the Scottish government has been re-elected with more MSPs than all the Unionist parties put together in the Scottish parliament and specifically, of course, on a manifesto promise.”